Using a ‘Tiny Bit of Math’ May Improve Your Heart Health, Study Suggests

Your average daily heart rate is a useful metric; so is your daily step count. Combining the two might be even better.

Many people use a smartwatch to monitor their cardiovascular health, often by counting the number of steps they take over the course of their day, or recording their average daily heart rate. Now, researchers are proposing an enhanced metric, which combines the two using basic math: Divide your average daily heart rate by your daily average number of steps.

The resulting ratio — the daily heart rate per step, or DHRPS — provides insight into how efficiently the heart is working, according to a study conducted by researchers at the Feinberg School of Medicine at Northwestern University and published today in the Journal of the American Heart Association.

The study found that people whose hearts work less efficiently, by this metric, were more prone to various diseases, including Type II diabetes, hypertension, heart failure, stroke, coronary atherosclerosis and myocardial infarction.

“It’s a measure of inefficiency,” said Zhanlin Chen, a third-year medical student at the Feinberg School of Medicine at Northwestern University and lead author of the new study; his coauthors included several Feinberg faculty physicians. “It looks at how badly your heart is doing,” he added. “You’re just going to have to do a tiny bit of math.”

Some experts said they saw wisdom in DHRPS as a metric. Dr. Peter Aziz, a pediatric cardiologist at the Cleveland Clinic, said it appeared to be an advance on the information provided by daily steps or average heart rate alone.

“What is probably more important for cardio fitness is what your heart does for the amount of work it has to do,” he said. “This is a reasonable way to measure that.”